This field-review is long, so I have divided it into three parts:
Part 1: Introduction and first impressions and handling.
Part 2: Shooting macro, lens selection, diffraction, autofocus performance and modes. Below.
Part 3: Shooting wide angle, lens selection, high ISO, dynamic range and conclusions.

MACRO
Macro shooting is one area where I felt the D3 would have some advantages and some disadvantages compared with a DX format camera. It turned out that way, but the differences were harder to spot than I expected.

I used the D3 with three macro lenses: Nikon’s 60mm AF-D and 105mm AFS VR and Sigma’s excellent F2.8 150mm macro lens. Wetpixel’s James Wiseman has been championing the Sigma for ages as an ideal macro solution for full frame cameras, particular when combined with Canon’s 500D dioptre. Basically it gives the same field of view as a 105mm gives on DX, and angle most find so suited to so many underwater subjects since converting to digital.

The FX sensor on the D3 returns the 60mm to its full angle of view. A main weakness of DX cameras for macro was that the 60mm had an equivalent angle of view on 35mm-film to a 90mm, which is a bit long for some subjects. This has driven quite a few of us to experiment with other lenses (such as Tokina 35mm, Sigma 17-70mm, and fisheye-teleconverter) on DX cameras to fill the gap. However, while on the one hand it is great to have the old 60mm back, on the other, I found myself surprised by the lack of versatility this lens offers on FX.

On DX, the 60mm is definitely the go-to focal length for macro flexibility. However on FX, despite being able to focus to 1:1, it is not as flexible a lens as I have got used to on DX. Both in Canada and California, my DX shooting buddies would be able to shoot a much wider range of subjects than I could with the 60mm. It just happens that nudibranchs sized critters are just the wrong side of the useful cut-off for this lens on FX and just the right side on DX. To shoot these subjects well on FX you need to get down close to 1:1, where the camera to subject distance is so short that it compromises lighting - I am talking small differences here. Of course it is still possible to light subjects at 1:1, I just feel that you do not get the same quality of lighting as you would on a longer lens at the same subject magnification. And who wants to take compromised images.

Of course what you loose on the swings you gain on the roundabouts. On FX, the Nikon 105mm VR becomes much more of the all-rounder, particularly when paired with a 5T dioptre. This weak dioptre shortens the minimum focus distance of the lens should you need to get closer than 1:1, without restricting the maximum focal distance too much. In fact the 5T would be a great teaching aid. If something is too far away with the 5T it is probably not worth shooting. Annoyingly the standard Subal 105mm VR port does not provide room for useful supplementary lens. I used it with my own port.

The 150mm with the 500D is something of a niche lens on DX. I use it regularly to achieve shots of common macro subjects with a fresh perspective. But I would be the first to admit that the difficulty of aiming a lens (with a film equivalent focal length of 225mm) generally means that I get a much lower hit rate than other macro lens. On FX I would agree with James that this lens becomes a mainstream lens, with an excellent return rate. One downside of the 150mm is that it made the Subal housing negatively buoyant and nose heavy, although Todd Mintz kindly lent me his buoyant StiX arms, which solved both the buoyancy and trim problems.

Perhaps my most surprising finding was that all three of these lenses were highly useful. On DX I could contemplate leaving the 150mm at home unless I had specific images I was after. On FX I would want all three with me on most shoots.

I will talk much more about the high ISO capabilities of the D3 when addressing wide angle. However, while shooting macro I was not creatively inspired by this ability and shot almost entirely on base ISO 200. On a couple of occasions I tried using ISO 800 to shoot balanced light macro, but found this quite a hassle. First you have to adjust ISO, then shutter speed and then flash power. With cold hands, in the chilly waters of British Columbia, my enthusiasm quickly waned for this technique. If this is a technique that appeals I would recommend ensuring you have TTL strobes, it is one less thing to adjust. Or don’t even bother changing the ISO and just slow the shutter speed down 3 or 4 stops and concentrate on holding the camera steady!

Perhaps the most common argument in favour of 12MP FX sensor over a 12MP DX sensor for macro underwater photography is diffraction at smaller apertures. In studio tests its possible to show that the more densely spaced the photosites on a sensor the more diffraction will occur reducing the detail captured at smaller apertures. While I do not doubt diffraction occurs in our underwater photos, I feel that in the real world there is so much else going on that influences sharpness (not least of which is shooting through murky seawater) that it is not such a limiting factor. When I shoot my DX underwater camera I do not see any significant reduction in sharpness between F11 and F22 (or more) – I just see more depth of field. And neither when I shot the D3 did I suddenly find that shots taken at F16, F22 or more were sharper than I had seen on DX at the same apertures. In respect of diffraction I did not find any practical advantage for using FX for macro on real subjects. I don’t believe that this is a factor that underwater photographers should be overly concerned with.

That said the D3 produced excellent image quality for macro. The pictures looked great on the LCD and even better on my Mac. I was actually surprised when I pulled up some D2X pictures and started examining them at 100% that there was not much to choose between the 12MP RAW files from each camera. The D3’s LCD had me convinced it was a step on in image quality!

In conclusion I found the D3 a fine camera for macro shooting once I had selected the appropriate lens for the appropriate subject. I didn’t feel that if offered any obvious advantages over a DX camera, but I was also pleased to discover it was not inferior in any way. Nikon’s new high-resolution 3 inch LCD is exceptional (and also found on the D300, D700 and D90) and leaves you in no doubt that you have nailed the focus and exposure.

AUTOFOCUS
I use autofocus for almost every underwater photograph I take and I value AF performance above many other factors when selecting a camera. On this shoot, I used a Fisheye FIX Light on all but one dive while in the dark waters of Port Hardy and San Diego and perhaps unsurprisingly the D3’s autofocus proved fantastic. It quickly and accurately locked onto just about every subject I wished to photograph. However, the wide, soft illumination from Fisheye Fix Light is so good that even poor AF will be flattered. So I made one dive in San Diego without the light and took the camera down to 20m (85ft) in viz of less than 5m (15ft) with no illumination and still found the AF very capable for macro. Nobody else on the boat considered shooting macro without a focus aid in these conditions, but the D3 could. In Guadalupe, photographing large subjects close to the surface it was unsurprisingly faultless.

Before trying the D3 underwater I had two concerns about the D3’s AF system. First I was frustrated that Nikon had decided to do away with the 5-point grouped AF that I use about 80% of the time on the D2X and second, I felt the poor frame coverage of the D3’s 51 point Multi-Cam 3500 AF module was limiting. I would happily have less points and more frame coverage.

To my pleasant surprise, the lack of a grouped AF mode was not a big deal. Unlike the D2X where I can generally stick to Grouped AF so much of the time, I found that the D3 worked best switching between the three AF Area modes for different scenarios, but once I got used to this I was very impressed. Jumping ahead to wide angle I found that Auto-Area AF worked very well on every subject I shot. Perhaps, only when shooting strongly backlit (into the sun) compositions might you need to switch to Single-Area AF. I also found that Auto-Area AF worked very well for many macro subjects too. The D3 has a rare ability to pick a subject out of the background and focus on it, with red squares blinking on the viewfinder to confirm the exact point of focus.

When shooting macro with an FX camera, the depth of field will be less than with a DX camera with the same framing at the same aperture and therefore it is important. Shooting FX is a reminder that DX shooting can develop some bad habits particularly sloppy “near enough is good enough” focusing. For this reason I would also use Single-Area AF when wanting to be very certain of focus. Port Hardy is an amazing dive destination with vertical rock walls plastered with super colourful sessile invertebrates (sponges, anemones, barnacles and soft corals). Hiding within this multicoloured jungle are lots of photogenic critters (nudis, crabs and characterful fish, such as sculpins and warbonnets). From a photographic perspective one of the biggest challenges is getting good subject isolation. We would all spend a lot of time searching for angles that would allow us to place subjects against open water. None of us believe in picking up and moving subjects for the sake of a shot. One appealing aspect of FX was the naturally shallower depth of field and I shot a large number of narrow depth of field or bokeh shots as Martin Edge classifies them, to include the colour of the background, but not the distracting details. I found the Sigma 150mm particularly affective, when opened up to F4.5-F6.3.

The final AF mode is Dynamic-Area AF, which I used with all 51 points activated and 3D tracking switched on in continuous mode. Initially we did not get on well, but the more I persevered with it, the more useful it became. By the end of the trip this was my main macro mode. In this mode all 51 AF sensors are active, however the 3D tracking can recognise the subject and track it, keeping it in focus around the frame. This works underwater, however, it does not work on all subjects particularly if they move fast. In other words don’t expect to be able to track an Anthias flitting around the frame in the current. I identified two main uses – both more to do with camera rather than subject movement! First is intention camera movement, this mode is a great tool for recomposing a macro shot. You leave the main focus point in the middle of the frame, focus on the subject, recompose and the camera tracks the subject “movement” and then fire. The second is in high magnification macro with longer lenses where it is impossible to keep the camera totally still. Here the 3D tracking is excellent and following the small movements resulting from camera and keep the subject sharp. Remember that in both cases I was making use of the illumination from the Fisheye FIX light in the dark Pacific waters. However, in the bright tropics I would expect this system to be even more impressive.

The AF frame coverage is perhaps my biggest complaint with the D3, the outer limits only just reaching the thirds of the frame. I feel that this is the only area where the D3 really falls below state of the art with its specifications. You can’t help conclude that the Multi-Cam 3500 system was developed for the D300 and then fitted to the D3.

Of course the camera has an AF lock button, with a lever that falls right below your thumb on the Subal housing, but I do not favour such a solution. Particularly with macro shooting, I want to have my AF point right on a key feature, such as an eye, ensuring it is razor sharp in my preferred composition. Surely this is more desirable that focusing, locking focus and recomposing while all the time trusting that neither you nor the subject moves. I hope that improved AF coverage will be on of the main upgrades when the D3 is replaced.

Continued in Part 3.